Reference
Ogal M, Johnston SL, Klein P, Schoop R. Echinacea reduces antibiotic usage in children through respiratory tract infection prevention: a randomized, blinded, controlled clinical trial. Eur J Med Res. 2021;26(1):33.
Study Objective
To determine if Echinacea purpurea extract can prevent viral respiratory tract infections (RTIs), secondary bacterial complications, and/or decrease antibiotic usage in children when compared to placebo.
Design
Randomized, blinded, controlled clinical trial across 13 clinics in Switzerland.
Participants
Out of 203 total participants, 187 healthy children (aged 4–12 years) completed this study, with 35.7% of participants being under 6 years of age. Males and females were of equal proportion in each group with no clinically significant differences between the 2 groups. One patient in each group discontinued the study due to an adverse event.
A total of 95% of the study participants had not taken echinacea or vitamin C for at least 3 months before treatment. Approximately 4% of patients in each group had previously received influenza vaccines, and 48.5% and 40.8% of participants in the echinacea and vitamin C groups, respectively, received the pneumococcal vaccination.
The exclusion criteria for this study included those “taking antimicrobial substances, salicylates or immunosuppressives, or if they had known diabetes mellitus, actively treated atopy or asthma, metabolic, autoimmune, degenerative or malabsorption disorders, liver or kidney disease or other severe health condition (cystic fibrosis or bronchopulmonary dysplasia), or allergy to the ingredients of the investigational medicinal products.”
Intervention
Healthy children were randomized 1:1 to receive either the intervention or the placebo. The intervention was 400 mg of Echinacea purpurea extract (Echinaforce®) 3 times per day, for a total of 1,200 mg daily. The echinacea extract comprised fresh, above-ground plant parts and roots, plant parts and roots, 380 mg and 20 mg, respectively, of ethanolic extract (plant to ethanol ratio=1:12 and 1:11, respectively, using 65% ethanol volume per volume).
The placebo was 50 mg of vitamin C (20 mg of ascorbic acid and 36 mg of calcium ascorbate) with natural orange flavor to make them indistinguishable from the intervention agent. This was also given 3 times per day, for a total intake of 150 mg of vitamin C daily.
Researchers dispensed both echinacea and the placebo in 2-month allotments. The average length of treatment was 4.1 months.
Study Parameters Assessed
Researchers instructed parents to record in a daily log the presence or absence of signs/symptoms in their children, including “‘runny nose’, ‘blocked nose’, ‘sneezing’, ‘headache and aching limbs’, ‘sore throat’, ‘cough’, ‘chilliness’, ‘disturbed sleep quality of the child’, ‘malaise’, ‘need for additional care-giving. These were rated as “absent” [0], “mild” [1], “moderate” [2], “severe” [3] or “severity not assessable.””
If symptoms warranted, they were also instructed to call the clinic and were given a throat swab to detect pathogens during acute infections.
Primary Outcome Measures
The primary outcome measure was the cumulative number of days of cold symptoms reported. This included any days in which the participant’s log was marked anything other than “absent” symptoms.
Secondary Outcome Measures
The secondary outcome measures included: total cumulative number of RTI symptoms and complications, total cumulative number of adverse events while taking echinacea or vitamin C, total cumulative number of adverse events reported possibly related to echinacea and vitamin C, and days with a fever and other flu-like symptoms.
Key Findings
This study demonstrated that echinacea extract seems to be effective and well-tolerated as a prophylactic treatment for RTIs and may help to decrease antibiotic usage in children compared to 50 mg 3 times per day of vitamin C.
The vitamin C group (n=98) had 47% more days (602 days) of experiencing RTI symptoms than the echinacea group (429 days; n=103; P<0.0001).
Echinacea group had 32.5% fewer RTI events (61 cumulative cold episodes) compared to vitamin C (86 cold episodes; OR=0.52 [95% CI 0.20–0.91, P=0.021]).
The number needed to treat (NNT) was 4 to prevent 1 RTI with echinacea.
Fever: The number of days with a fever decreased from an average of 4.9±6.61 days in the vitamin C group to 1.6±4.34 days in the echinacea group (P<0.001).
Subjective observation: More parents (89.8%) of the children in the echinacea group stated that they believed the treatment had improved resistance than in the vitamin C group (70.8%) (P=0.010).
Viral load/pathogen testing: There was significantly less abundance of viruses detected from nasopharyngeal samples in the echinacea group (57) compared to the vitamin C group (72; P=0.0074). There were 20 samples of influenza found in the vitamin C group compared to 3 samples in the echinacea group (P=0.012).
RTI complications: There were 11 patients (10.7%) experiencing RTI complications in the echinacea group compared to 30 patients (30.6%) in the vitamin C group (P<0.0030) with an absolute risk reduction of 65.0% for the echinacea group and 19.9% for the vitamin C group.
Antibiotic usage: There were 6 children (5.8%) in the echinacea treatment group who took antibiotics for a total of 45 days compared to 15 children (15.3%) taking vitamin C for a total of 216 days. This resulted in a relative risk reduction for antibiotic use of 76.3% and an absolute risk reduction of 18.7% (P=0.0012) over a period of 4 months. There were 1.67 fewer days of antibiotic treatment in the echinacea group compared to the vitamin C group over 4 months, adding up to 4.98 fewer days of antibiotic usage for each child over an entire year. The NNT=5 with echinacea for reducing antibiotic usage and RTI complications compared to vitamin C.
From the perspective of parents and investigators, there were no significant differences between the tolerability between the echinacea group and the vitamin C group, and most of them rated both agents as “very good.”
Adverse events: Two patients from the vitamin C group (2.0%) and 3 patients from the echinacea group (2.9%) reported an adverse reaction possibly due to treatment. The adverse reactions in the echinacea group included diarrhea, urticaria, and choking.
Practice Implications
Echinacea species are widely used in the Western world to help prevent and treat common colds.1 Determining its efficacy is challenging due to the high risk of bias in many of these studies,1 including this one. Previous studies have shown that echinacea has not been shown to have statistically significant results against placebo in treating the common cold, although it has been shown to be more beneficial when used early (prophylactically) with a slight risk of adverse effects.1
The results of this current study by Ogal et al are promising, but due to the high risk of bias and the small sample size, more research needs to be done to be conclusive. That being said, the study suggests echinacea (Echinaforce) is a relatively safe and effective prophylactic treatment for children who are not immunocompromised, taking steroids (eg, for asthma), or with allergies to echinacea and/or ragweed.2
Researchers conducted a small study over a period of 10 days with 11 children with recurrent upper RTIs. In it, they were given echinacea extract (2.5 mL three times daily for ages 2–5 and 5 mL twice daily for ages 6–12), and the results showed decreased symptom severity as well as confirmed safety and tolerability.3 These are promising results, but due to the small sample size and short duration, the results are not as meaningful as they could be. Regular follow-up visits with thorough patient intakes, histories, and physical examinations should be done to reduce the risk of potential adverse effects.
Although it is vital to decrease the risk of RTIs, along with their related complications and antibiotic use, it may not be feasible, convenient, or safe to recommend an herb such as echinacea to every child for long-term prophylaxis.
In the current study under review, researchers used an ethanol-based echinacea extract for the treatment group, which has been previously shown to be effective at preventing recurrent RTIs as well as reducing the risk of related complications.4 This is of utmost importance to keep in mind as water-based extracts such as pressed juices have not been shown to have any significant efficacy.4
A systematic review and meta-analysis was published in 2019 that gathered data on the efficacy and safety of echinacea for treating or preventing upper respiratory tract infections (URTIs) in people of all ages.5 They concluded that it may help in prevention, and short-term use is recommended as it reduced the risk of adverse effects in comparison to long-term use.5
When it comes to treating children, safety is paramount. Although it is vital to decrease the risk of RTIs, along with their related complications and antibiotic use, it may not be feasible, convenient, or safe to recommend an herb such as echinacea to every child for long-term prophylaxis. With this in mind, there are a number of other naturopathic modalities for cold and flu prophylaxis with much less likelihood of causing harm, such as hydrotherapy, nutrition, and homeopathy. All of these can be recommended to otherwise healthy pediatric patients before recommending any herb for long-term use. Long-term, prophylactic use of echinacea in children may be indicated for those at increased risk of recurrent RTIs, with due consideration for the risks versus benefits of such a recommendation. Other than that, echinacea may be indicated for children at the first sign of cold/flu symptoms until they are no longer experiencing them as long as there is no apparent allergy or hypersensitivity reaction.
